Substitute for catgut and similar animal products and the manufacture thereof



Patented Jan. 3, 1928 UNITED STATES PATENT OFFICE.

ALBERT ERNEST PENFOLD, REGINALD TRUESDALE, AND ROBERT CHARLES SMITH, OF

BIRMINGHAM, ENGLAND, ASSIGNORS TO THE DUNLOP RUBBER COMPANY, LIM- ITED, OF BIRMINGHAM, ENGLAND, A BRITISH CORPORATION.

SUBSTITUTE FOR CATGUT AND SIMILAR ANIMAL PRODUCTS AND THE MANUFACTURE THEREOF.

No Drawing. Application filed March 16, 1927, Serial No. 175,919, and in Great Britain December 17, 1925.

This invention relates to the manufacture of a cord or string suitable as a substitute for gut and similar'animal product such as is used for stringing racquets of the kind used for playing lawn tennis, badminton and other games. It is also equally suitable for garden and tennis nets, fishing lines and the like, or for strings for musical instruments.

According to this invention we form a cord or string of the type described by im-,

pregnating a number of threads of silk, ramie, cotton, wool, hemp, jute, artificial silk, or other fibres or fine threads with a 5 solution of deresinated gutta percha or deresinated balata or both to which rubber may be added together with vulcanizing in redients if desired. The threads are twlsted together in a die immediately after or during the process of impregnation.

We are aware that finished goods have been assed through a bath of solution with the o ject of im regnating the same and theyhave. been su sequently vulcanized but 2 in such recesses the impregnation cannot be so satisfactorily efl'ected as in the proc-' esses accordin to our mvention.

The said so ution may be made up of the following ingredients.

80 Parts by weight. Deresinated gutta percha. 7 5 1st grade plantation rubber 20 Sulphur 5 If necessary a vuleanizin accelerator may beused such as light calcine magnesia. The above ingredients are combined with and agitated n a solvent such as toluene. The roportion of solvent added varies accordmg to the'viscosity of the solution required.

'Such proportions may be 25 parts of ingredients and 7 5 parts of solvent, both by weight.

As an alternative solution we may a utilize Parts by weight. Deresinated gutta percha 90 Sul hur 5 60 Lig t calcined magnesia. 5

prepared as aforesaid, but it will be underthat both the aforesaid solutions and stood of suitable size, heated by warm air or other suitable means, at a suitable speed to ensure that the said cord is within the heated cham her for a suflicient period to achieve the desired end.

The threads, may, if desired, before vulcanization be given a further coating or coatin s of solution after the threads are twisted, together.

Further the im roved gut may be coated, before or after vu canizatio'n, with a suitable varnish to impart finish thereto.

It is, of course, understood that we may employ the fibres referred to either separately or one or more of them together in anyproplortions desired.

e cords may if desired be characterized by a composite construction, additional threads being twisted in the manner described around a central core or cord which also may be formed in the manner hereinbefore described.

It will be a parent that the said core may be constitute by any suitable attenuated material, for instance, so called catgut or again by wire which may be suitably braided or twisted if desired.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is The process of producing a string possessing characteristics enablin its su stitution for gut, comprisin indivi ually impregnating separate stran s in a solution contamin a relativel large percentageof deresinated gutta-perc a and a relative y small percentage of sulphur, the proportions being about surface of the string to give it the characfifteen t0 twenty-three-percent deresineted teristics first stated.

gutta percha to one and one-half percent In Witness whereof, We have hereunto sulphur, by Weight, then twisting the imsigned our names.

pregnated strands together and subjecting the twisted strands to pressure to form the ALBERT ERNEST PENFOLD. single string of close cross section, and REGINALD TRUESDALE. finally vulcanizing, drying and finishing the ROBERT CHARLES SMITH. 

